1. Field of the Invention
The present invention relates to a device for the collection, storage, and transfer of a blood or specimen sample obtained from a patient for medical diagnostic testing. More specifically, the present invention relates to a device for collection of blood samples from a patient. The device also includes a cap assembly having a stopper for closing and sealing the device after the blood or specimen sample has been collected. The stopper incorporates space elimination features to funnel the blood or specimen sample to a probe assembly of a testing instrument during transfer from the collection tube.
2. Description of Related Art
Conventional capillary collection devices typically provide a microtube or collection container having a raised receiving lip or funnel feature that engages the skin surface of a patient that has been pierced, so as to draw a blood sample from the capillaries located just beneath the skin surface. The internal collection cavities of conventional collection containers are typically straight-walled and do not provide any specimen flow-enhancing features. Conventional containers typically do not promote the flow of drawn blood into the cavity during the collection process, and a typically not structured to allow direct withdrawal of a sample from within the cavity by standard instrumentation. Accordingly, a significant amount of the collected blood or specimen sample is trapped on the sidewall of the cavity due to surface tension during collection and during transfer.
After collection, conventional collection containers are typically sealed by a cap assembly disposed on the collection container. Conventional cap assemblies typically provide a flat bottom surface in communication with the collection cavity. As a result, a significant dead volume amount of sample is trapped within the collection cavity during transfer of the specimen, since neither the collection container nor the cap assembly adequately funnel or channel the collected blood sample to the aspiration hole of the probe needle. As can be appreciated, conventional collection assemblies retain a significant amount of wasted sample within the container. This requires that a significantly greater volume of sample must be collected within the collection container than is actually required to perform the necessary diagnostic test. The volume of sample collected is particularly important in capillary applications, in which a very small volume of blood is typically available. The avoidance of waste specimen is therefore a particularly important concern. Also of concern is the exposure of a specimen to medical practitioners during the sampling procedure, and compatibility of the collection container with standard diagnostic and analysis instrumentation.
Accordingly, there is a need for a fluid sample collection device, container assembly, and associated fluid sample collection methods in which the amount of sample collection, typically blood collection, characteristics are improved. There is also a need for an improved collection assembly which is compatible with standard diagnostic and analysis instrumentation. There is further a need for an improved collection assembly in which exposure of medical practitioners to a specimen during a sampling process is reduced.